Tachycardia, orthostatic hypotension and profound weakness due to concomitant use of fluoxetine and nifedipine.

The use of the selective serotonin reuptake inhibitor fluoxetine is associated with only minor cardiovascular effects. However, due to a possible inhibitory effect on the metabolism of calcium channel blockers it may potentiate the activity of nifedipine, causing profound adverse cardiovascular effects. This report describes the appearance of profound weakness, orthostatic hypotension and tachycardia following the initiation of fluoxetine treatment in a nifedipine-treated 80-year-old patient.